1. Field of the Invention
The present invention relates to a curable organosilicon composition that is useful as a curable silicone material, an encapsulating material for optical devices such as optical elements, an encapsulating material for other electronic devices such as semiconductor elements, and an electrically insulating coating material, and also relates to a cured product of the composition.
2. Description of the Prior Art
In recent years, the output of blue light emitting diodes (LED) and white LEDs has increased, and they are now starting to be used for mobile telephone flashes, backlights for liquid crystal displays, and for general illumination. However, this increase in the LED output has lead to increases in the quantity of ultraviolet light emitted and the quantity of heat generated, meaning the materials used for constructing the devices require better levels of light resistance, heat resistance and crack resistance.
Coating and encapsulating materials for LEDs require favorable transparency, and although conventional epoxy resins exhibit a high degree of hardness and superior crack resistance, they are known to undergo discoloration when exposed to ultraviolet light or heat, which leads to a deterioration in the LED output.
The use of silicone resins has been investigated as one potential solution to the above discoloration problem. Soft silicone resins generally exhibit excellent heat resistance, but they suffer from poor workability and are prone to dirt and dust adhesion. Furthermore, although hard silicones provide excellent workability and handling properties, they tend to suffer from inferior crack resistance.